package org.bouncycastle.asn1.x509;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERTaggedObject;

public class V2Form extends ASN1Encodable {
    GeneralNames issuerName;
    IssuerSerial baseCertificateID;
    ObjectDigestInfo objectDigestInfo;

    public static V2Form getInstance(ASN1TaggedObject obj, boolean explicit) {
        return getInstance(ASN1Sequence.getInstance(obj, explicit));
    }

    public static V2Form getInstance(Object obj) {
        if (obj == null || obj instanceof V2Form) {
            return (V2Form) obj;
        } else if (obj instanceof ASN1Sequence) {
            return new V2Form((ASN1Sequence) obj);
        }

        throw new IllegalArgumentException("unknown object in factory");
    }

    public V2Form(GeneralNames issuerName) {
        this.issuerName = issuerName;
    }

    public V2Form(ASN1Sequence seq) {
        if (seq.size() > 3) {
            throw new IllegalArgumentException("Bad sequence size: " + seq.size());
        }

        int index = 0;

        if (!(seq.getObjectAt(0) instanceof ASN1TaggedObject)) {
            index++;
            this.issuerName = GeneralNames.getInstance(seq.getObjectAt(0));
        }

        for (int i = index; i != seq.size(); i++) {
            ASN1TaggedObject o = ASN1TaggedObject.getInstance(seq.getObjectAt(i));
            if (o.getTagNo() == 0) {
                baseCertificateID = IssuerSerial.getInstance(o, false);
            } else if (o.getTagNo() == 1) {
                objectDigestInfo = ObjectDigestInfo.getInstance(o, false);
            } else {
                throw new IllegalArgumentException("Bad tag number: " + o.getTagNo());
            }
        }
    }

    public GeneralNames getIssuerName() {
        return issuerName;
    }

    public IssuerSerial getBaseCertificateID() {
        return baseCertificateID;
    }

    public ObjectDigestInfo getObjectDigestInfo() {
        return objectDigestInfo;
    }

    /**
     * Produce an object suitable for an ASN1OutputStream.
     * 
     * <pre>
     *  V2Form ::= SEQUENCE {
     *       issuerName            GeneralNames  OPTIONAL,
     *       baseCertificateID     [0] IssuerSerial  OPTIONAL,
     *       objectDigestInfo      [1] ObjectDigestInfo  OPTIONAL
     *         -- issuerName MUST be present in this profile
     *         -- baseCertificateID and objectDigestInfo MUST NOT
     *         -- be present in this profile
     *  }
     * </pre>
     */
    public DERObject toASN1Object() {
        ASN1EncodableVector v = new ASN1EncodableVector();

        if (issuerName != null) {
            v.add(issuerName);
        }

        if (baseCertificateID != null) {
            v.add(new DERTaggedObject(false, 0, baseCertificateID));
        }

        if (objectDigestInfo != null) {
            v.add(new DERTaggedObject(false, 1, objectDigestInfo));
        }

        return new DERSequence(v);
    }
}
